In current disk grinding apparati, a cylindrical surface included for grinding is rolled over a grinding disk that is controlled by a cam plate. However, due to the grinding disk resting with its edge on the cylindrical surface, the formation of ridges on the surface to be processed cannot be avoided. In fact, in a worst case situation, turning of the surface may be required, followed by equalizing and finish grinding which, in most cases, involves several time consuming working steps. In addition, the turning and subsequent grinding operations contribute to the wear of the cylinder, thus reducing the overall life of the cylinder to be processed. These subsequent operations are particularly difficult and expensive at the ends of the cylinder which have slightly convex edges and require special devices to achieve acceptable results.
It is further necessary to preheat the turning and grinding machines over long periods of time since the machines are not protected against the radiating heat of the heat cylinder.
An apparatus of this type is known from DE-OS 36 39 264. Here, between two brackets mounted on columns, a support and an adjustable guide rod acting as a guideway and having a form corresponding to the set value of the spherical surface accuracy are provided. On the guide rod and the support, a grinding belt device that includes a grinding belt drive, a feed slide with adjusting devices and axially displaceable guide bushings and a clamping device are located.
A disadvantage which generally prevails in the precision grinding of worn cylindrical surfaces is that, initially, the partial surfaces projecting from the cylindrical surface are removed. In the case of heated cylinders, different radiating conditions are created between the machined and unmachined surfaces which leads to different temperatures in the cylinder wall. Consequently, differential thermal expansions are caused in the machined and un-machined partial surfaces.